The present invention relates to a television picture transmission system in which a transmitting section comprises a picture information components producing member, anti-aliasing filters for filtering said picture information components, a picture movement analyser for producing on the basis of the picture information components a quantity representing the movement therein, an output member of the anti-aliasing filters for coupling the input of a sub-sampling circuit to outputs of the anti-aliasing filters, said output member being controlled by the quantity representing the movement, a transmitter circuit for transmitting the information components from the sub-sampling circuit via a transmissiom channel and an information multiplexer for applying to the transmitter circuit in addition to the information from the sub-sampling circuit, output information of a threshold member, in which system a receiving section comprises a receiver circuit for receiving transmitted information components, interpolation filters for oversampling the information received, a receiver member for receiving the quantity representing the movement, an output member of the interpolation filters for supplying the useful information and a demultiplexer circuit for on the one hand applying the samples received to the interpolation filters and on the other hand separating the information originating from the threshold member from the samples received.
The present invention also relates to a transmitter and a receiver appropriate to the system.
Such a system meets important applications in the transmission of high-definition television pictures. The problem met in such a transmission is that one is compelled to use transmission channels having a narrow passband. This passband does not allow a transmission of all the information components of the picture recorded at studio level. It is consequently necessary to sort the information components and to transmit only those information components which render it possible to provide a picture of the best possible quality at the receiver side.
In an article by Yuichi Ninomiya et al., "A single channel HDTV broadcast system-the Muse" published in NHK Laboratories, serial no. 304, September 1984, and in the European patent application No. EP-A 0,146,713 a system of the above-defined type is disclosed which provides a solution for this problem. The anti-aliasing filters are then formed by two filters, one of which acts on the still pictures and the other one on the moving pictures.
The drawback of this known system resides in the fact that there is disparity between the definition of the transmitted pictures when these pictures contain still sense and when the pictures contain moving scenes. Namely, this definition varies from single to double in the two cases, which is particularly visible when the movements are only slight and concern a large portion of the picture.